It seems the KDE spin lacks the "extra" folder. As I understand how this should work, we pass a command via grub to force the load of the tmp_tis module, which probably will depend on tpm itself. As you do not have tpm_tis in the KDE spin kernel, this fail. Thus no suspend using this spin.
It seems the KDE spin do not install the package kernel-modules-extra by default.
I do have it in the Gnome spin :
$ yum list installed | grep kernel-modules-extra
kernel-modules-extra.x86_64 3.14.8-200.fc20 @updates
kernel-modules-extra.x86_64 3.14.9-200.fc20 @updates
kernel-modules-extra.x86_64 3.15.4-200.fc20 @updates
And this package provides what we need:
$ repoquery --list kernel-modules-extra | grep tpm
/lib/modules/3.15.4-200.fc20.x86_64/extra/drivers/char/tpm
/lib/modules/3.15.4-200.fc20.x86_64/extra/drivers/char/tpm/tpm_atmel.ko
/lib/modules/3.15.4-200.fc20.x86_64/extra/drivers/char/tpm/tpm_infineon.ko
/lib/modules/3.15.4-200.fc20.x86_64/extra/drivers/char/tpm/tpm_nsc.ko
/lib/modules/3.15.4-200.fc20.x86_64/extra/drivers/char/tpm/tpm_tis.ko
Try install it:
$ su -c 'yum install kernel-modules-extra'
Hopefully, this will fix your issue.